1. Field of the Invention
The present invention relates to a technology for controlling recording of data in a cache and a memory provided in a processor.
2. Description of the Related Art
Conventionally, an input/output (IO) device outputs a data store request to a system controller that controls data recording in a main storage device. When a sequential guarantee is necessary for the store request, the IO device needs to await a completion notification (hereinafter, “storage completion notification”) for the store request from the system controller before outputting the subsequent store request to the system controller.
However, depending on whether data corresponding to a store request address is found in a cache in a central processing unit (CPU), the system controller that receives the store request issues an invalidation request for the data in the cache and also records in the main storage device, the data (hereinafter, “storage target data”) that is to be stored. Upon completion of an invalidation process for the cache and recording of the storage target data, the system controller outputs the storage completion notification to the IO device.
Consequently, the IO device cannot output the subsequent store request until the storage completion notification from the system controller is received, so that the storage target data cannot be processed rapidly.
To resolve the above problem, a technology is disclosed in Japanese Patent Application Laid-open No. 2000-181891, in which upon receiving the store request, a storage control device that controls input and output of the data stored in the main storage device sends, without awaiting completion of storage target data recording, the storage completion notification to a store request source once the data invalidation process is complete.
However, in the conventional technology, with an increase in the storage target data that is processed by the IO device, a circuitry for managing the storage target data becomes complicated and the storage target data cannot be efficiently managed.